LTE-M - Technology for mobile IoT projects

The Internet of Things (IoT) continues to expand. By the end of 2020, IoT Analytics counted around 11.7 billion IoT connections worldwide. By 2025, this figure is expected to exceed 30 billion, and analysts are forecasting a stronger influence of LPWA technologies on IoT devices as a result. In this regard, LTE-M is the leading LPWA technology for connectivity of industrial applications in the Internet of Things (IoT). The complementary service offers lower latency and higher throughput for IoT applications. In the application scenario factory site, this is a clear benefit.

LTE-M (also LTE-MTC / LTE Cat-M1/2)

LTE-M is the abbreviation of LTE technology for Machine-type Communications. The standard is based on 3GPP specifications and thus on technology building blocks from 4G and 5G. The 3rd Generation Partnership Project (3GPP) creates globally valid standards for data transmission and has thus also defined the LTE standard. In comparison between Low Power Wide Area Networks (LPWAN) LTE-M is recommended for the transmission of high data rates. Up to 7 Mbit/s in the uplink (from the sensor to the network) and up to about 4 Mbit/s in the download (from the network to the sensor) are possible. However, transmission requires a wider frequency band than NB-IoT: LTE-M devices typically support bandwidths between 1.4 and 5 MHz.

The special designation of LTE-M with a maximum bandwidth of 1.4 megahertz is LTE Cat-M1. In the assigned frequency spectrum, LTE-M can also transmit data between the IoT devices through walls or lower-lying rooms. The building penetration of the signals is very high over long distances in the communication network. Thus, LTE-M is particularly recommended for IoT applications where ordinary cellular networks run dry in a dead zone and network coverage is no longer guaranteed. In addition, the latencies in the wireless network are significantly lower when transmitting via LTE-M. Mobility is another strength of this LTE coverage. Write and read speeds are similar to those of conventional, broadband mobile communications connections via 4G and 5G in the same LTE location. This means that if required, SMS or voice messages can also be transmitted with low energy consumption and high penetration (gain around 10 dB) in the upload direction.

Types of LTE-M

There are three versions of LTE-M in the 3GPP standard: Cat-0, Cat-M1 and Cat-M2. Cat stands for category and describes the development stage of the standard. Accordingly, Cat-M1 and Cat-M2 represent a further development of Cat-0. The difference in the development from LTE Cat-0 to LTE Cat-M1 is that the bandwidth is only 1.4 megahertz instead of 20 megahertz. This makes the Cat-M1 version much more energy-efficient to use. With Cat-M2, 3GPP has again raised the bandwidth to five megahertz. This means that this LTE-M standard can also accommodate higher data rates. Frequently, LTE-M providers use the simple designation LTE Cat-M to mean LTE Cat-M1.

LTE-M: Greater bandwidths for stationary and mobile IoT applications

LTE-M is the abbreviation for Long Term Evolution for Machines. With the introduction of this standard, the general usability of IoT systems was decisively expanded. The complementary service has been optimized for the transmission of data. With the ongoing network rollout, LTE-M is manifesting itself in the industrial sector worldwide as a future-proof alternative for older mobile technologies. 2G and 3G have already been switched off in some countries or will no longer be available in the coming years. As a result, LTE-M has established itself as a service with low frequency spectrum in many places alongside narrowband IoT (NB-IoT) in the communications network. Both standards are supported by leading telecommunications bodies and mobile network operators and benefit from global network coverage. This ensures the most important feature of LTE-M.

Keyword: mobility. In end-to-end processes with business customers, mobile IoT applications with larger bandwidths, or data volumes, are necessary. For example, when the provider has to install a new firmware update on the connected IoT devices. For this purpose, the service uses the benefits of LTE coverage as well as current encryption methods to make the data transmissions between the devices unreadable for third parties. Another benefit is the entire tracking of IoT devices in use. Using signal transmission in LTE-M, a transmitter in a transport container can report where it is at regular intervals - smart tracking. Another use case is health trackers that report important data on the health of its owner to a central location at fixed times - e-Health. The mobility factor makes LTE-M the ideal standard for IoT solutions in which movement plays a fundamental role:

Wearables
e-health sensors
asset tracking
Smart city applications with higher data volumes (e.g., traffic monitoring)
Alarm and security systems
Remote control and predictive maintenance of machines
Smart factory (and smart home) applications

In Germany, LTE-M and narrowband IoT penetration continues to gain ground. In 2020, Vodafone cited the value of approximately 90 percent network coverage in Germany. The penetration of LTE-M is closely linked to the availability of the LTE network, so network coverage will continue to increase with the LTE rollout in Germany. So far, network requirements are best met in the major cities. Locally, the major network operators and IoT providers have already implemented individual projects for smart city applications - for example, in the area of e-health and for tracking goods on transport routes (smart tracking). **Numerous LTE modules act as interfaces to ensure data exchange between the mostly commercial IoT applications.

LTE-M modules: The standard in its operational application

As a standard, LTE-M offers numerous benefits and can be used in a wide range of applications. However, the LTE-M standard alone is only the theoretical basis for carrying out data transmission between IoT devices in networks. The actual functionality is found in the LTE-M modules. Firmware that is built into the embedded systems of IoT devices to transmit the data. In this context, LTE modules exist that support both LTE-M and narrowband IoT. Such a LTE-M module is the connectivity board from grandcentrix. This allows us to ensure transmission between devices in an individual IoT solution. It also supports both LTE Cat-M1 and narrowband IoT standards.

NB-IoT and LTE-M: Two standards for stationary and mobile service

Low bandwidth, low power consumption, good building penetration and long range - with these benefits, LTE-M and Narrowband-IoT will become the standard for IoT applications in 4G and 5G. Both standards are tightly interwoven with existing mobile networks. In addition, both services are a component of the specifications for 5G mMTC implementations envisioned in the future. Embedding them in cellular standards makes the investment in LTE-M or narrowband IoT future-proof - regardless of your choice.

In direct comparison, the different benefits of LTE-M and Narrowband-IoT are obvious. **NB-IoT is recommended for stationary monitoring of IoT devices and IoT applications due to its transmission structure. In smart parking, a parking sensor reports whether the parking space is free via NB-IoT. A typical use case in the smart city. With lower latency and higher bandwidth, LTE-M, on the other hand, is perfect for mobile use - for example, in smart tracking of vehicles, packages and their respective delivery status within complex logistics centers.

Based on existing hardware components grandcentrix creates customized solutions for your IoT applications and business models in the Internet of Things. Especially in narrowband IoT we see ourselves as a specialist for connectivity of highly individualized solutions with complex connectivity requirements. Since 2010, we have been implementing your customer-specific IoT projects with over 200 employees from Cologne. In addition, our solution portfolio for NB-IoT has grown strongly since 2020 in the Vodafone group.

Term	Definition
3GPP	3rd Generation Partnership Project (3GPP) is a worldwide cooperation of standardization committees for standardization in mobile communications; specifically for UMTS, GSM, LTE and 5G/NR.
LTE-M	LTE-M or LTE-Cat-M1 stands for LTE for Machines and is also known as Enhanced Machine-type Communications, or eMTC for short. It is a supplementary 3GPP standard (Release 13) for LTE. It enables an LTE network operator to equip its mobile network for typical applications in the Internet of Things (IoT).